Endometrial thickening is a finding on ultrasound, which can more accurately measure the thickness of the endometrium. Clinically, endometrial thickening is diagnosed when the thickness of the endometrium exceeds the upper limit of the normal range on ultrasound. The first 2 weeks of a woman’s menstrual cycle is called the follicular phase. The endometrium in this period is relatively thin, with 1cm as the limit, and if it is greater than 1cm, it is considered to be endometrial thickening. The 2 weeks after a woman’s menstrual cycle is called the luteal phase. The lining of the uterus is thicker in this period than in other periods, with 2cm as the limit, and if it is >2cm it is considered to be endometrial thickening. When a woman enters menopause, the lining of the uterus will begin to gradually shrink, at this time 5mm as the boundary, if > 5mm is considered to be endometrial thickening. If endometrial thickening is clearly present, further hysteroscopy and curettage should be performed if necessary. Endometrial thickening in postmenopausal women is often considered to be endometrial polyps, endometrial hyperplasia, endometrial cancer and other diseases. It is recommended to check for endometrial thickening, and should go to regular hospitals for further examination and treatment according to their own conditions, so as to avoid delaying the condition.